truly reflective surfaces


(d52477001) #1

ok… i’m doing a house scene and there is a mirror so i created it using an envmap but then when I moved the camera the reflection was all wrong… :frowning: … Is there any way to create a truly reflectivve surface? if not, is there any way how i can fake it??

btw - thanx far all you guys’ great(!) help…


(S68) #2

No there is not.

YOu must animate BOTH the camera AND the empti in a way the empty is always in the right place with respect to the camera (i.e. on the mirror image of the cvamera)

Then, in the EnvMap settings press ‘Anim’ and not ‘Static’ so that the EnvMap is re-computed at each frame.

Hey!

I never said this was going to be fast

Stefano


(SKPjason) #3

And that’s why I love S68… it’s not a simple world… we should NEVER expect simple answers… :wink:

:smiley: Jason


(haunt_house) #4

Is it possible to animate another camera, so that you don´t need to render six images, but one and then use the avi as an animated texture?

should save time if possible

Did someone succeed in this?


(S68) #5

Mmmm…

Not sure it is possible.

The EnvMap created this way it is a image containing six sub-images defining a cube around the Empty.

A viewer placed in the center of the cube would see the entire scene correctly.

A single camera would do, at most, a single face of the cube and it absolutely not guaranteed that you need only one face for the reflection. You may need more.

You can think of placing the camera so that it gets all you need but this way it would not be a face of the cube and would not be remapped correctly.

Furthermore the Empty stuff is automatically computed, while a second camera is not and would need python scripting…

So…

Stefano


(IamInnocent) #6

And to make the matter even more complicated : this same work would be a child’s play with any raytracer… and faster most likely. :slight_smile:


(haunt_house) #7

Ididn´t mean to substitute envmaps entirely.

He spoke of a mirror, so the surface in question would be flat. by the way: which setting is necessary to env map decently to a spehre?

Especially when I have world enabled, I can clearly see the cube heritage.

regards
HH


(S68) #8

Faster? Naaaaa!!! Have you ever tried?

Envmaps works great for Plane and spheres alike, it is the other shapes (i.e. cylinders etc which are seldom accurate)

If you find odd things with words it may be because you have left settings to the default and not to ‘Real’

Maybe…

Stefano


(haunt_house) #9

OH praise to you, wise and mightyy forum god

so I´ll take your ‘maybe’ and use it as a ‘definitely’

thanks

religious Haunt_house


(IamInnocent) #10

Faster? Naaaaa!!! Have you ever tried?

Well, yes, otherwise I wouldn’t have said it. Although I’m not about to imagine some benchmark to proove a point, I find that an envmap big enough to avoid pixellization in most cases is quite a long process. For a moving camera, one must have a new envmap for each frame… as I said : likely. I usually use POV


(S68) #11

\me starts thinking to the benchmark :slight_smile:

Stefano


(fullback) #12

d52477001 Posted: 08 May 2002 02:36 Post subject: truly reflective surfaces


ok… i’m doing a house scene and there is a mirror so i created it using an envmap but then when I moved the camera the reflection was all wrong… … Is there any way to create a truly reflectivve surface? if not, is there any way how i can fake it??

Are you trying to do something similar to this?

http://www.geocities.com/whitmore1000/blend/video.htm (cut and paste)

I did this a while ago using a script by JMSoler. http://jmsoler.free.fr/didacticiel/blender/tutor/cpl_scriptmirror.htm

Took a long time to render because the env map has to be animated, like S68 said, AND you need a very large cube res to make a convincing mirror.


(IamInnocent) #13

:smiley:

It would have to be really particular : soft shawdows are quite faster (and better, with some limitations due to the buffer size and bias) than and equivalent area light. Transparency is also faster in Blender but so lame that I almost always set it to 100% and… and then use an envmap ! Then you’d have to choose the raytracer : I use POV.
So, no shawdows, no transparency… no AA since it is quite difficult to compare settings from one renderer to the other… and a whole lot of mirrors, since the rendering time are getting quite short on modern machines for a simple mirror, lower than one second indeed… in raytracing that is.
:stuck_out_tongue:


(IamInnocent) #14

It would be somewhere in there :
http://jmsoler.free.fr/didacticiel/blender/tutor/english/index_prog_python.htm

The guy’s name is Soler, Jean-Michel.


(fullback) #15

The guy’s name is Soler, Jean-Michel.

Oops. Sorry.


(IamInnocent) #16

I’ve called him “Solers” part of a year, finally corrected myself but kept thinking he was “Jean-Marie” till Christmass. So, you see…

:wink:


(IamInnocent) #17

I’ve run some test and… if you use the mirror as a camera (select the mirror and do ctrl+0, that is zero on the numpad ; alt+NUMPAD 0 to view through the camera again), render a view of the scene and image_map the mirror with it… well, it is usable, unless the mirror is the main character of the scene or you aim with the camera at shallow angles. But it certainly is fast and there’s some interest to play with the focal angle. One can even distort the image subtly in a 2D apps so it looks like ancient glass/mirror, somewhat uneven, hidding somewhat the flaws of the process.

Well, I’ve tried… :-?